(11a) principle of conservation of linear Momentum states that in any system of colliding objects the total momentum is always conserved provided that there is net external force acting on the system.

(11bi)

Impulse IA = change in momentum of A

= final momentum of A

- initial momentum of A

MAVA - MAVA

Impulse IB = change in momentum of B

= MBVB - (MBUB)

= MBUB

12a . decay constant is define as the instantaneous rate of decay per unit atom of a substance.

12bi)The moderator is a material which slows down the speed

of the neutrons . The moderator is

usually made from water but some reactors use graphite .

12bii) Control rods are used for maintaining the desired state of fission reactions within a

nuclear reactor (i.e. subcritical state, critical state, power changes) They constitute a key component of an

emergency shutdown system (SCRAM) .

Control rods are rods, plates, or tubes containing a neutron absorbing material (material with high absorbtion cross-section for thermal neutron) such as boron , hafnium, cadmium , etc., used to control the power of a nuclear reactor . By absorbing neutrons, a control rod prevents the

neutrons from causing further fission

We appreciate you for reading Codedexam, but we think it will be better you like our facebook fanpage and also follow us on twitter below.
Follow @Codedexam

Are you an artiste? Do you want your music to go viral and reach a large number of audience? Promote your music on Codedexam.com by clicking here. You can also advertise your product or brand by clicking here.